The present invention relates to a sintered composite composed of sintered powders of different materials and a method of manufacturing such a sintered composite.
It has long been practiced to heat metal powder or nonmetal powder into a sintered product. It is also customary in various fields of art to sinter powders of different materials into sintered composites having improved heat resistance, abrasion resistance, rigidity, and sliding capability.
For example, aluminum powder and aluminum alloy powder or copper powder and copper alloy powder are mixed and sintered into a sintered composite for use as a sliding component material such as a bearing material. It is however difficult to mix such different powders uniformly and hence to make a uniform composite material from the powders. If powder of a softer material such as lead or tin is mixed when iron-base metal powder is sintered into a sliding component such as a bearing, then the produced sliding component has an improved sliding ability because its sliding surface can well slide against other objects. However, the softer material such as lead or tin cannot easily be dispersed uniformly in the iron-base metal powder. In addition, since the melting points of lead and tin are lower than the melting point of iron, if the powder mixture were sintered at a sintering temperature for iron, e.g., 1000.degree. C., in an inert gas atmosphere or a reducing atmosphere according to the normal sintering process, then lead or tin would completely be melted and flow downwardly.
There has been developed a metallic material which has a repulsive capability like a rubber ball. However, any metallic material which is viscoelastic at normal temperature, like rubber, is not available yet. If such a viscoelastic metallic material were developed, it would be soldered or spot-welded to an existing metallic material, and would find a wide variety of applications. Therefore, demands for the material are growing in the art.
A sintered composite of synthetic resin and metal would be lightweight and highly rigid, could be formed easily into desired shapes, and would be of high machinability. There is also a strong demand for such a sintered composite.